Riding mower



FIG. 1 is a left side view of a riding mower, showing our new design;

FIG. 2 is a right side view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The ornamental design of a riding mower, as shown and described.